APP: User Replication Fails

Symptoms

Anveo User replication failed showing an error message like:

Unable to connect to the remote serverThe remote server name could not be resolved: servernameThe remote server returned an error: (401) Unauthorized.The remote server returned an error: (404) Not found.Service ".../Codeunit/Task_Communication" was not found.

Cause

Communication settings between Microsoft Dynamics NAV and Anveo Server are not set up correctly.